London Three-time world footballer of the year Lionel Messi told The Times yesterday that he will retire from football the day he feels he is no longer having fun.

The 24-year-old Argentinian - who scored 73 goals in 60 games for Barcelona last season, breaking the European club record of 67 goals set by Bayern Munich's Gerd Mueller in 1972-73 - hinted that for him the fun was going out of the game in general.

Messi said that he was trying to be the epitome of a 'pibe' - a man boy who is fearless in running at older players with the ball at his feet and a magical dribbler shorn of all inhibitions.

"A pibe! That's what I am trying to do," he said.

"Football is a game. I'm trying to have fun on the pitch, always just to play. That's why I do it. The day I stop having fun is the day I retire." "I never want to lose that spark, that passion." "Today teams are playing more statically, more for the final score than producing good football. For them its more important to win than to play well. We need more players with passion coming up for the good of football." Messi, who was brought to Barcelona aged just 13 by his steelworker father and was taken on after a brilliant trial despite his suffering from Growth Hormone Disorder which was remedied by the club with hormone therapy, said despite his goal-scoring record last season there was 'the one that got away' that stayed with him.

It came in the Champions League semi-final second leg at the Camp Nou against Chelsea as the holders looked to press home their one man advantage after the English side's skipper John Terry was sent off at the end of the first-half.

Barcelona were awarded a penalty early in the second-half and Messi stepped up to take it only to miss - Chelsea were to go on to draw the game 2-2 and progress 3-2 on aggregate.

"I felt terrible," he said.

"Angry at myself because I knew that at that moment the whole tie was in my hands, but I can't do anything about it now. It's past but it was a very tough moment for me and I still think about it." Messi says that while he is grateful for all that he has experienced so far he still has much to learn.

"I am playing for one of the best teams in history," he said.

"I'm very grateful for everything I've been able to achieve, for the family I have, for the people who surround me." "But I always believe better things will come, I want to grow and mature as a person. I still have so much to learn. I am the way I am at every moment. I am not playing a role." "It makes it easier to be myself. I don't have to watch what I do. I just do what I do. And remember I am only 24 years old."